Shane Rattenbury is stepping down as Member of the Legislative Assembly of the ACT, after 18 years in office.

For the entire duration, the ACT Greens have been in sole balance of power in the Legislative Assembly – that is to say, they have been the only bloc that decides which party forms government.

From what The Australia Institute can tell, this makes Rattenbury the longest-ever MP in a Westminster democracy to serve in (sole) balance of power.